Gerald Böhm

[33] Thermostability of proteins from Thermotoga maritima

Publisher Summary Proteins, independent of their mesophilic or thermophilic origin, consist exclusively of the 20 canonical natural amino acids. In the multicomponent system of the cytosol, these are known to undergo covalent modifications at the upper limit of temperature observed in the biosphere. Extremophiles must compensate for these degradation processes either by using compatible protectants or by enhanced synthesis and repair. Many studies on the thermal stability of proteins have focused on enzymes from hyperthermophiles. In this context, Thermotoga maritima , with its temperature range of growth between 55° and 90°, has become one of the favorite organisms, because it is widespread in marine geothermal vents as well as in low-salinity solfataric springs, it can be cultivated in large-scale fermentations, and it has been characterized in detail with respect to its metabolic requirements. The bacterium is a strictly anaerobic fermentative organotroph that grows on various sugars, cellulose, starch, and glycogen as the carbon source: peptides are required for growth on carbohydrates because the organism does not utilize ammonia or free amino acids as the N source.